I know that the device has to remain on the Matrix during the hardware test and I thought I had read that the device could not be used during that period as well, but I can't find that last bit anywhere in the book or after a brief search online. The remaining on the Matrix bit is from the German book and might even be in the reprint of the English book, but is otherwise not in the errata. At any rate, as Tecumseh says, leaving the couple behind could be a problem if anybody thinks to check their place for any reason. Adding another layer of complexity to the plan (not a good idea, but I'll bring it up anyway), we could have Doc (because, really, he's just sitting around doing nothing through all this - not) trigger their health alert or something when the house goes boom. Might make it look like they went into shock from the nearby explosion, at least until they have a more thorough examination.
Or, we could knock them out and take them with us. Dump them somewhere after the ownership change is complete. The less they see of our faces, the better, but at this point any criminal activity would likely be linked to us as primary suspects anyway. Our only saving grace is that possibly our pursuers have left the local authorities out of things thus far, so we might have that advantage. But Ohanzee at least is a person of interest in Gloria's disappearance (I still wonder if an anonymous tip to her body's location could pit the authorities and our pursuers at odds), so he at least has to keep a low profile.
Only issue with Chino intercepting the spirits is that since he can't astrally project, he isn't going to be able to do much intercepting. He can help fight them when they get here, but since they would be able to inform their summoner of their status via the spirit-summoner link, it wouldn't really prevent our discovery. We could try to lure them to a different location (Ohanzee or Kat could lure them) and them all of us beat them senseless. Since they wouldn't have discovered our location, it could reset their search, and since they were the only witnesses to Ohanzee, that could basically end it.